Process for drying articles and apparatus for accomplishing the same.



F. A. SECORD.

PROCESS FOR DRYING ARTICLES ANDVAPPARATUS FOR ACCOMPLISHING THE SAME.

APPLICATION FILED NOV. I7. |915. I

' Patented Apr. 3, 1917.

2 SHEETS-SHEET l.

fmvena F. A. SECGRD. PROCESS 'FOR DRYING ARMCLES AND APPARATUS FoRACCOMPUSRING THE SAME. A-PPLICATION. FILED; NOV. I7. 1915.

2 SHEETS-SHEET 2.

Patented Apr. 3, 1917.

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FREDERICK AVARD SECORD, OF ST. JOHN, NEW BRUNSWICK, CANADA, ASSIGNOR OFONE-THIRD T0 ALEXANDER' PIERCE PATERSON AND ONE-THIRD T0 CI-lARLES HENRYPETERS, OIE' ST.,^JOIIN, NEW BRUNSWICK.

:PROCESS lEOlR. DRYING ARTICLES AND APPARATUS FR ACCOMPLISHINGITHE SAME.

meines'.

Application filed November 17, 1915. Serial No. 61,871.

To all whom t may concern: y

Be it known that l, FREDERICK AVARD SnooRD, a citizen of the UnitedStates, residing at St. John, in the county of St. John and Province ofNew Brunswick, Canada, have invented new and useful Improvements inProcesses for Drying Articles. and Apparatus for Accomplishing the Same,of which the following is a specification.

rlhis invention relates to improvements in processes for dryingmiscellaneous articles and more particularly, though not exclusively, toarticles constructed of plastic material, such as brick, tile, potteryand the like, and for subsequently burning or baking said brick, tileand the like.

Furthermore, this invention relates to apparatus for accomplishing thesame. The

present system of drying brick, tile and thev like consists in placingthe Wet clay from which4 said 4articles are .constructed within suitablechambers and subjecting the same' to excessively high temperaturesvarying from 120O to 300 F. and sometimes higher. These temperaturesmust be maintained for a considerable length of time in order tothoroughly d ry said clay. 'To maintain such temperatures in any degreeof uniformity involves considerable expense and time.

Specification of Letters Patent.

Patented Apr. y3, i917.

rial constituting said clay develops severe internal stresses whichproduces cracks between said layers consequently destroyingthefinishedtile orv brick and'resulting in a large percentage of loss tothe manufac- The application .of so much heat to the.

clay, although previously considered essential, produces severalvobjectionable results, for instance, intense .heat contacting with theouter layers of the cla-y quickly evaporates the moisture from saidouter layers and before the moisture from the interior of the clay hashad a chance to spread or be conducted by capillary attraction orotherwise to the outer layers thereof, said outer layers have becomequite dry, causing the material constituting the same to shrink andclose the pores thereof. l

The result of this drying and shrinking is to form a crust which retardsthe escape of the moisture within said clay and more especially whensuch escape mustbe accomplished by the conversion of the moisturetherein into vapor. Such a state of affairs naturally prolongs thedrying process of the turer.

- After the brick-or tile has been dried as thoroughly as is possiblewith this system, it is placed within a suitable kiln where it is againsubjected to a comparatively low temperature at first to insure thecomplete drying thereof before the final heat for baking is applied.This precaution is of particular '65 importance, principally for thereason that to apply the final heat to material such as clay which isnot thoroughly dry would immediately cause said clay to explode., lnaddition to the moisture which must inevitably remain within the clayafter the drying process has'been completed as far as possible, saidclay in-being transferred from the drying ,chamber to the kiln is moreor less exf posed tothe atmosphere fromwhich it very readilya-bsorbs oraccumulates more or less moisture during such transmission, and this`moisture must alsobe 'removed before said final heat is applied. Afterthe burning or baking h'as been completed a considerable period of timemustbe consumed with.. the ordinary methods, in cooling the burntproduct which coo-ling process must be uniform and gradual in order toprevent unequal shrinkage of the several layers of said clay.

The object of the present invention is to provide a process vfor dryingand subsequently baking or burning'articles of the nature set forth,whereby the forming of a crust, andexposure to. the atmosphere duringthe drying process and the transference. thereof from the dryingapparatus to the 'kiln may be eliminated, 'and a considerable reductionin the length of time required to complete the drying, subsequent bakingand final. cooling of the clay, may be secured.

l Another 'object of the invention is to provide instrumentali'tiesadapted/to produce` and to maintain Wide ranges'of temperatures in orderto accommodate the-drying and baking of articles ofsdifferentcharacters.

Still anotherobject of the invention is tov provide means for.. removingsubstantially all moisture from the air which is to be used in thedrying process and in tempering said air. l

Another object of the` invention is to provide instrumentalitiesconstructed and arranged to supply-predetermined quantities of salt andammonia saturated airto thev chambers within which the drying or burn`ing of the clay takes place in order to produce a glaze upon the surfaceof the finished product.

The invention consists primarily in the improved process hereinafter setforth in the specification and claims, which consists in artificiallyreducing the temperature of the clay and in removing moisture from thesurface of the clay after it has been thus artificially reduced byapplying currents of air to the surface thereof.

The invention further consists in the improved processand in thecombination and arrangement of parts of the apparatus whereby the aboveobjects and otherobjects hereinafter appearing may be attained as setforth in the following specification and particularly pointed out intheyclaims.

Referring to the drawings:

Figure 1 is a somewhat diagrammatic l. view of an apparatus adapted to.accomplish the several steps of the process embodying my invention.

Fig. 2 is a section taken on the line 2-2 of Fig. 1, illustrating theinterior of the drying chamber.

Fig. 3 is a section taken on the line 3 3V of Fig. 1, illustrating thepreferred form of gate for separating the several compartments of thedrying casing from each other.

Fig. 4 is a section taken on the line 4 4 of Fig. 1, illustrating thedampers for controllingthe temperature within the drying chamber and themeans for operating the same.

Like numerals refer to like parts throughout the several views of thedrawings.

In the drawings, 6 represents a .casing which is preferably subdividedinto L plu-c rality of compartments, in the present instance three areindicated at 7, 8 and 9 respectively.

` The particular design and construction of the casing 6 may varyaccording to the location, Acapacity and pressures required. Thepreferred form, however, is cylindrical as illustrated, with severalcompartments being separated from each other by gates- 10' while theopposite-ends of the casing are adapted to be closed by gates of thesame character', the preferred form of which will be hereinafter morefully described.

A track 11 extends through the several compartments of the casing 6permitting a car or truck 12 to be moved entirely through said casing.To occupy as little space as possible the gates 10 are arranged to slidetransversely of the casing 6 in inclosed casings 13.

A shaft 14 extends transversely of each gate and has secured thereonpinions 15 adapted tofengage racks`16 on said gates Awhich upon therotation of said shaft cause Y at 18 in which the articles which havebeen passed through the several compartments may be stacked for thepurpose of burning or what isv sometimes termed baking. A passageway 19has been provided to connect the compartment 9 which in the presentinstance is the last compartment in the casing G, with the interior ofsaid kiln 18.

In order to successfully carry out the several steps of the processembodied in this invention, it is essential that instrumentalities beprovided for maintaining the air in each one of the several compartmentsof said casing and likewise in the kiln 18'at a preapparatus 20 has beenprovided and preferably consists of a.' brine tank 21 within whicharearranged a series of coils 22 of pipe through which ammonia isadapted to be circulated from a tank 23 by electrically driveninstrumentalities 24. The electrically driven instrumentalities 24 arecontrolled by a switch 25 which, in turn, is controlled by a thermostatof any of the well known types arranged within the brine tank 2l andadapted to be operated when the brine in said tank has reachedapredetermined temperature, to operate the switch to open or close theelectrical circuit controlling said electrically driveninstrumentalities.

From the brine tank 21 there extends a pipe 27 which passes into acooling chamber 28 also providedl with a series of pipes 29. A retin-1rpipe 30 connects said series 29 ducting the cold air of the temperature'fea ' point, to increase or diminish the supply of cooled brine tofsaid coolingchamber.

A' pump- 33 is arranged to provide the necessary circulation of saidbrine from the brine tank to the series of pipes 29 withinl the coolingvchamber 28. A supply of air may be admitted to the cooling chamber 28either from the atmosphere through an inlet pipe 34, from the casingthrough a pipe 35, or from the brine tank 21 through a pipe 36, each ofsaidv pipes being provided with suitable dampers 37. From the coolingcham-4 ber 28 means have been provided for condetermined by thelthermostat 32 to each of the compartments 7,' 8 and 9 of the casing 6and to the kiln 18 through an airl conductor 38 to whichis connectedbranch pipes 39, 40 and 41 communicating with the compartments?, 8 and 9respectively and a branch pipe 42 extending to the kiln 18.

A blower 43 is installed in the conductor 38 preferably adjacent to thecooling chamber 28 so as to force the cold air from said cooling chamberinto all of said compartl ments. Several methods may be employed fortempering the air which is conducted from the cooling chamber 28 to theseveral compartments of the casing 6 and also the kiln. The preferredmethod of accomplishing this result, however, is to provide anotherbranch-pipe 44, preferably connected with the pipe 38 adjacent to theblower 43.

The pipe 44 passes through a plurality of coils 45 ofheating pipe 46connected withl some suitable source of heat.

The pipe 44 is provided with branches 47,

48 and 49 which unite respectively with the branches 39, 40 and 41 ofthe cold air conductor 38 while another branch 50 is con- 'nec/:ted withthe kiln 18. In order that the temperature of the air which is suppliedto the several compartmentsmay be regulated.

and maintained at the desired point, means have been provided forautomatically regulating said temperature, said regulating meanspreferably consisting of a pair of dampers 51 and 52 arranged in thecold and hot air` conductors slightly in advance of the" point at whichsaid conductors unite adjacent to their connection with the severalcompartments.

Each of said dampers is provided with a spindle 53 which projectsthrough the conductor within 'which it is located and has secured to theouter end thereof a pinion 54.

A rocker arm 55 pivoted at 56 -betweenthe two dampers 51 and 52 isprovided with a segmentally arranged series of teeth 57 at opposite endsthereof which engagethe pinions 54, and upon being rocked, cause thedampers 51 and 52 to be simultaneously operated with their spindles. Therelative positions of said dampers with respect to each other issubstantially at rightl angles so that when one is entirely closed theother s will be wide open, whereby a current of air equal to thecapacity of on conductor may always be passing therethrough.

The rocker arm 55 is connected by means of a link 58 preferably with alever 59 attached to one end of a rocker shaft 60 which extends throughthe wall of the casing 6. To the opposite end of said shaft 60 issecured another lever 61 which, in turn, is operatively connected to thestem 62 of the thermostat of any of the well known forms adapted to beexpanded or contracted by varying temperatures within the casing 6 andwhich may beset at a predetermined vso temperature so that the leastvariation of aol the point determined. l

The regulating instrumentalities fo-r the several compartments and alsothe kiln are preferably substantially identical so that a description ofone will suliice. ,i

Another important step in the system of drying substances is to reducethe pressure of the air within one or all .of the compartments of saidcasing 6 and 1n order that this may be accomplished the pipe 35 has 105been extended to each of the compartments 7, 8 and 9 and a damper 63, isprovided adjjacent to the connecting polnt of each of said'branches withits respective compartment so that said compartments may be connectedwith or shut off from the pipe 35.

fA- blower 64 is connected with the pipe 35 for the purpose ofexhausting the air from. said compartments. A branch pipe 65 is suppliedfor discharging the air which 115 is .exhausted from the compartments 7,8 and 9 to the atmosphere when desired, said pipe being provided with adamper 66. The kiln 18 1s connected through an air conductor 67 with thebrine tank 21 through 120 which air may be forced in one direction orvthe other by ablower 68 connected therewith.

The preferred method of drying articles of the nature hereinbefore setforth in the 195 apparatus described is as follows:

`The material to be dried is placed upon the car 12 and moved'into thelirst compartment 7 of the casing 6. The gates 10 at opposite ends ofsaid-compartment are then then operatedY to withdraw' the dry air fromclosed. The atmospheric air within said compartment 7 is then preferablywholly or in part withdrawn by operating thel blower 64 so as to removesubstantially all moisture from said compartment. This air may,l ifdesired, be forced through the pipe `v and discharged through thedischarge Preferably,

pipe f 65 dto the atmosphere.4 however,y this air is adapted to beturned into the cooling chamber 28 within which*l said'cooling chamberand force 4the same through the conductor 38 to the compartment 7. Theair as it passes. into the compartment 7 being at such a low temperaturecauses more o r less moisture within the clay which is in saidcompartment to also condense 'upon the surface of said clay.

When the temperature of air has been reduced to substantially 39.2 F.saidair will .be as free from moisture as it will be possible to makeit. In like manner, if the clay within the compartment 7- is exposed foral predetermined. period to the same tempera- -ture the moisturelwithinsaid'clay will be brought to the surface thereof and' there condensed.Air, the temperature of which has previously been reduced tosubstantially "39.2 F. and subsequently increased, is then passedthrough the compartment 7, and the moisturewhich has been condensed onthe surface of the clay within the chamber referred to will be readilyabsorbed by said air and thus remove the condensation from saidcompartment and said clay. y

The air thus tempered is never heated to al. temperature high enough toform a crust upon the surface of the clay, and therefore the pores ofsaid clay will remain open until substantially every particle ofmoisture l therein has been removed. The tempered air` hereinbeforereferred to may be. ad-

-' mitted'to the compartment 7 after cold air -has -been passedtherethrough or, if desired,

the cooling of the clay may takewplace in said compartment 7 andtheremoval of thel moisture therein be accomplished in the next compartmentof the series. vThe apparatus,'howe ver, is constructed so as to permiteither system to be employed.

To accomplish the tempering of the airl hereinbefore referred to, ecoils of the pipe 45 are arranged along the branch pipe 44 said coilsbeing heated and adaptedv to conveyconsiderable heat to the air as it isconducted through the pipe 44. After the temperature which is mostadvanta eous for the drying of fclay or like articles asbeen determined,the thermostat or temperature regulating apparatus may be set and thevalves or dampers 51 and 52 automatically operatedthereby to maintainwhatever temperature has been previously determined. When the claywithin the compartment 7 has becomesuiciently dried and ready for thekiln', the gate between said compartment 7 and the next compartment 8may be opened and the car pushed along into said next compartment. 4 l

Previous to the admission of said clay to said compartment 8 theatmospheric air within said compartmenty should preferably be removed bymeans of the blower 64 connected therewith through the conductor 7 0,and replenished with absolutely dry air .from the cooling chamber 28Vwhich air is preferably tempered somewhat above that within thecompartment 7 The temperature Within the compartment 8 maybeautomatically controlled and regulated by means of the thermostat 69connected to thedampers 51 and 52 arranged Within the branch pipes 4()and 48 which unite to supply air to the compartment 8. The nextcompartment 9 of the series of compartments is preferably heated to atemperature substantially above that of the compartment 8, but insubstantially the same manner through thev conductors, 41 and 49.

' The temperature in the compartment 9 is preferably the same as thatwithin the kiln 18 which may be supplied with air of a predeterminedtemperature through the conductors 50 and 42 which are connected withthe conductors 38 and 44. This arrangement of the conductors and airsupplying instrumentalities. permits the temperature of the kiln to beadjusted at will to accommodate the workmen who transfer the tile orclay from the casing 6 to said kiln. The several compartments with theexception of 7 are vpreferably forthe purpose of gradually increasingthey temperature of said clay during its transfer from the dryingchamber to the kiln s0 as not to expose the clay to` any sudden changesof temperature andalso to eliminate any possibility of said clayabsorbing any moisture after it has "been dried and while being movedfrom the dryingmchamber tcVthe kiln. y After the baking of the clay hasbeen accomplished and before it is removed from the kiln, it must becooled. To accomplish this result air heated to a predeterminedtemperature may be admitted through the conductors 42 and 52 from theair cooling and heating instrumentalities 28 and 45 respectively, untilthe clay is cool enough to be removed from lsaid kiln. The temperal theconductors 42 and `ture of the air entering said kiln through 50 may be`gradually reduced by means of the dampers 51 and 52 arranged in thepipes42 and 50.

It isl sometimes desirable to utilize the heat from the kiln to assistin heating the dry air l/from the ,cooling 'chamber 28. l To accomplishthis result a blower 71 has been connected with the hot air conductor 50so that the dry hot air from theukiln may be conducted into the severalcompartments 0f the casing 6. L

'It has been stated that one of the objects of the invention lis toprovide instrumentalities constructed and arranged to supplypredetermined quantities of salt and ammonia saturated air to thechambersewithin whichthe drying or burn-ing of the clay takes place inorder to produce a glaze upon the finished" product. To accomplish thisresult the brine tank 21 has been connected by means of an airconductor,36 with the cooling chamber 28. Another air conductor 67 connects saidbrine tank with the'kiln 18, thus air may be drawn through said brinetank which, in passingtherethrough, will absorb salt and ammonia vaporswhich may then be conveyed either to the kiln direct or to the severaldrying and tempering compartments through the cooling chamber 28 andconductors 38'and 44. The blower 68 the same is transferred to the vsaidapparatus. Furthermore,

facilitates the transfer of said salt andam- 'monia laden air from saidbrine tank to the A kiln while the blower 43 is sulicient to convey thenecessary proportions ofsalt the compartments 7, Sand 9.

It will b e obvious that with the apparatus air to hereinbefore setforth articles greatly differing'in character and substance may be driedowing tothe wide range offadjustment of removal of moisture fromu theclay -before kiln will be assured and the absorption of moisture-by theclayas it is transferred from co-mpartments to the kiln will beabsolutely prevented.

The time required for completing the entire drying and baking processwillv 'be greatly reduced as compared with that consumed withythe-systems now employed, for the reason that the exact temperatureofthe several compartments, best suited to the drying, baking andlcooling may be maintained for any length of time, or changed at 'will tohasten or retard the same without regard to the condition 0r temperatureof the atmosphere outside, which condition seriously afthe complete thedrying supply dry. tempered air of a predetermined temperatureto theseveral furnaces of the kiln wh-ich willi result in a considerable"saving in time over the present methods employed. y

To render. this possible, the kiln 18, which is preferably circular, issurrounded bya chamber 73 which embraces all of the furnaces of saidkiln, one of which is illusvtrated in section at 74, and as this is, insubstantially all respects, similar tto the other furnaces connectedwith said kiln, but one -has been shown. The chamber 73 hasoommunication with the passageway 19 but is adapted to be shut off fromsaid passageway by suitable gates 72.

Tempered air, which has previously been reduced toa temperaturesubstantially 39.2 F. is adapted to be conducted to the chamber 7 3through a branch pipe 7 5 connected with f the cold air conduct-0r38'and a'hot air pipe 7 6- connected with the hot air conductora-544 and49. With this arrangement of the conductors, a great saving of 'time andexpense will result, owing to the removal.l of the moisture from the airbefore it is admitted tothe furnaces and also to dition of said air.

Having thus described my invention what I claim and `desire .by LettersPatent to secure is: l

l. A process for drying clay which consists'in placingsaid clay within aclosed casing and then in circulating through said case' ing and incontact -with said clay currents of air having a temperatureartificially reduced to substantially 39.2 F. until the temperature ofsaid clay is thusarticially reduced and' then continuing the circulationof currents of air in 'contact'with said clay until the moisture at thesurface of said clay is removed. v

2. A process for drying 'clay which consists,rst.in artificiallyreducing the temperature of said clay and second in removing moisturefrom the surface of -said clay by applying curren s of air' to thesurface thereof. 'Y

3. A process for drying clay which consists in placing the material tobe dried within a closed casing, then vin passing through said casingand in contact with said the tempered conclay currents of air having atemperature4 artificially reduced to substantially 39.2 F. until thetemperature of said clay is thus a1'- tificiallyz'reduced and then inartificially increasing substantially the temperature of said currentsof air, whereby moisture is removed from the surface of said clay andfrom said casing.

4.v A process for drying clay which consists first in artificiallyreducing the temperature of said clay by applying currents of air oflower temperature than that of said clay to the surface thereof, andsecond in removing moisture from said clay by applying currents of airto the surface thereof.

5. A process for drying clay which consists first in artificiallyreducing the temper- 'ature of said clay by-applying currents of air oflower temperature than that of said clay to the surface thereof andsecond in removing moisture from said clay by applying currents of airof increasing temperature to the surface thereof.

6. An' apparatus for drying and baking clay having,`in combination, akiln and a .drying casing', each adapted-to contain clay,

means vfor 'reducing the temperature of lair,

means for circulating said a1r. through said,

casing and .said kiln and in contact with said clay, said circulatingmeans including a pair p of conductors, means for heating the air in oneof said conductors and instrumentalities for automatically regulatingthe amount of` air passing through said conductors and 1nto said casingand kiln, whereby the temperature of the airI circulating through-saidcasing and kiln may be regulated.

7 In an apparatus for drying clay, a cas-- ing for said clay, a pair ofconductors connected with said caslng, instrumentalitles constructed andarranged to remove substantially all moisture from the air passingthrough said conductors, heating instrumentalities arranged adjacent toone of said conductors, means for forcing the moisture-less air throughsaid pair of conductors into said casing and instrumentalitiesconstructed and arranged to automatically mix air from said l heatinginstrumentaliti'es with the air in the other conductor whereby said airmay be heated to the desired temperature.

8. In an aparatus for dnying clay a series of casings, means adapted toopen and close communication between the several'casingr of said series,means for conveying the ma- Y terial to be dried successively throughsaid series of casings, means for conducting air to each of the casingsin'said series, instrumentalities constructed and arranged to removesubstantially all of the moistureffrom the air passing into saidcasings, instrumen- 'talities constructed and arranged \to heatFREDERICK AVARD SEGOB-D.

Witnesses SYDNEY E. TArr, n 'Hmm ELSTRATTON.'

